The Zoom-FFT is a process where an input signal is mixed down to baseband and then decimated, prior to passing it into a standard FFT. The advantage is for example that if you have a sample rate of 10 MHz and require at least 10Hz resolution over a s

本文介绍了一种复合信号测量系统，该系统基于TMS320F2808实现，用来检测和重建复合频率信号中的主次信号。该系统由计算模块、重建模块和通讯模块组成。为了能在实时运行中自适应地确定采样频率，我们采取了“eCAP+AD”的方法，eCAP模块记录下整形后的复合信号的上升沿过零点时间值并估计出主频率，从而使系统能自动地选取合适的采样频率完成AD采样过程。系统采用了4096点的FFT算法，能够实现高达0.25Hz的频率分辨率，相对分辨率达到0.05 。-This paper introduces a